// process tapset
// Copyright (C) 2006 Intel Corporation.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.


function _IS_ERR:long(ptr:long) %{ /* pure */
    THIS->__retvalue = IS_ERR((const void *)(long)THIS->ptr);
%}


/* probe process.create
 *
 *  Fires whenever a new process is successfully created, either as a result of
 *  one of the fork syscall variants, or a new kernel thread.
 *
 * Context:
 *  Parent of the created process.
 *
 * Arguments:
 *  task - a handle to the newly created process.
 *  new_pid - pid of the newly created process.
 */
probe process.create = kernel.function("copy_process").return {
    task = $return
    new_pid = task_pid(task)
    if (_IS_ERR(task)) next
}


/* probe process.start
 *
 *  Fires immediately before a new process begins execution.
 *
 * Context:
 *  Newly created process.
 */
probe process.start = kernel.function("schedule_tail") { }


/* probe process.exec
 *
 *  Fires whenever a process attempts to exec to a new program.
 *
 * Context:
 *  The caller of exec.
 *
 * Arguments:
 *  filename - the path to the new executable
 */
probe process.exec = 
    kernel.function("do_execve"),
    kernel.function("compat_do_execve") ?
{
    filename = kernel_string($filename)
}


/* probe process.exec_complete
 *
 *  Fires at the completion of an exec call.
 *
 * Context:
 *  On success, the context of the new executable.
 *  On failure, remains in the context of the caller.
 *
 * Arguments:
 *  errno - the error number resulting from the exec
 *  success - a boolean indicating whether the exec was successful
 */
probe process.exec_complete =
    kernel.function("do_execve").return,
    kernel.function("compat_do_execve").return ?
{
    errno = $return
    success = (errno >= 0)
}


/* probe process.exit
 *
 *  Fires when a process terminates.  This will always be followed by a
 *  process.release, though the latter may be delayed if the process waits in a
 *  zombie state.
 *
 * Context:
 *  The process which is terminating.
 *
 * Arguments:
 *  code - the exit code of the process
 */
probe process.exit = kernel.function("do_exit") {
    code = $code
}


/* probe process.release
 *
 *  Fires when a process is released from the kernel.  This always follows a
 *  process.exit, though it may be delayed somewhat if the process waits in a
 *  zombie state.
 *
 * Context:
 *  The context of the parent, if it wanted notification of this process'
 *  termination, else the context of the process itself.
 *
 * Arguments:
 *  task - a task handle to the process being released
 *  pid  - pid of the process being released
 */
probe process.release = kernel.function("release_task") {
    task = $p
    pid = $p->pid;
}